AVI-IO - miscellaneous information
This page provides miscellaneous information of AVI-IO.
The following limitations are known to exist in AVI-IO.
With some capture hardware it's always necessary that the "Video Format" is set
before you try to capture the first time. Otherwise you get an message box
"Error initializing capture!" This is however not a limitation of AVI-IO. It's
a driver issue.
AVI-IO currently only supports PCM audio formats.
We are considering the following extensions of AVI-IO:
You may have noticed that the player part of AVI-IO does not have player
controls. We will add such controls which will allow you to move back and
forth along the footage defined in the play list as if it would be one single
We are further improving support for DV cards (IEEE1394 boards). This includes
device controls, print back to tape and support for some boards using propriatary
Note, AVI-IO does some internal buffering of frames to allow to do it's job
perfectly. The I/O Buffer's on the status line show how many buffers are currently
allocated and what the maximum is. It's shown to help you set the optimal
data rate your capture hardware can handle. The number must stay below the
maximum, or the capture process will be terminated. Generally spoken you should
adjust your data rate so as the number of allocated buffers usually does not go
above 20. Like this you have a "security" buffer zone to allow for short "hicks"
your HD system might have. Like this frame drops are avoided that other capture
software would experience in the same situation. Again, this does not really
allow you to set a higher data rate, but it makes AVI-IO run smoothly avoiding
dropped frames where ever possible. It's normal that even at lower settings you
see the number of I/O Buff's bounce.
The tool (on all platforms) will create individual AVI's of up to 4GB (2GB
on FAT16 formatted drives) size each. Please note however that most Windows
video software (players, NLE and the like) do not really work with files
bigger than 2GB. Note that the player part of AVI-IO will play such files
Be aware that there are players NOT capable of playing files bigger than 1GB.
This applies for instance if you try to play an avi over the "Properties" ->
"Test" tab in explorer.
Note, if needed AVI-IO insert's frames to keep synchronization between audio
and video, while all other capture tools known to us don't. Such capture tools
(as a consequence) may not report any drop's BUT audio and video shifts in such
cases if you capture over long periods. We feel that inserting frames (and
reporting them as drops) is better than letting audio and video shift, because
such shifts are soon noticeable especially if you capture talking people. The
reason for such shift's (if they happen at all) is caused by the sound card
and/or video capture card used. If one (or both) of these devices do not keep
exactly the frequency requested by you (i.e. 29.97 fps 44100Hz or whatever)
audio and video will shift if you capture using a different capture
tool. AVI-IO corrects this behavior only if needed giving perfect lip
synchronized captures over hours using even unstable (cheap) hardware!!!
- The drawback are some reported drops which however should not be noticed
If you experience crashes or get the error message "Not enough RAM", make sure
virtual memory is turned on. Also make sure that there is enough free HD space
available on the drive where the swap file is located (usually drive 'C').
In case you use a Pinnacle DC10+, make sure to set the video output and
preview option in the DC10+ control panel. You can open the control panel by
double clicking on the Pinnacle logo in the taskbar. Without this option AVI-IO
cannot successfully play back video with this board.
In case you use a buz together with the morgan MJPEG software codec, make sure
to set drivers section in your system.ini file as follows:
Change it back if you need the Morgan codec. We are considering a checkbox in
the player settings which allows to overcome this inconvenience.
DV (Digital Video) boards
Currently AVI-IO supports OHCI compliant boards or any other DV board as long as
there is a Video for Windows capture driver installed for it, or a working WDM
DirectShow wrapper. The support is currently limited to capturing only
and also does not include device controlls. Boards known to work well are the
ADS Pyro, the Exsys, SIIG and Pinnacles Studio DV. You need Windows 98SE or
Windows 2000 or better, since only those platforms have a working WDM wrapper.
Note the following information is important to make AVI-IO work wiht DV
- The camcorder must be turned on and transmitting a DV datastream to
the computer before you start up AVI-IO. To achive this with some camcorders
you must set them to VCR mode, and hit "Play"
- If AVI-IO seems to freeze, make sure the camcorder is sending DV Data. Note,
this is a limitation of the WDM Video for Windows wrapper and not a limitation of
- You must set the propper framerate under capture settings (29.97 fps for
NTSC, 25fps for PAL)
- It does not matter what audio format you choose or if you have configured
one already. AVI-IO will adapt the audio format to the one it finds on tape.
- If AVI-IO detects a frame which is having a different audio format than the
previous one, the capture stops. You can then continue from this spot with a
new capture. This is because it's not possible to change the audio format in an
avi file "on the fly".
- There is no preview visible if you don't have a Video for Windows DV codec
installed in your system. Preview is not needed to capture DV video with AVI-IO.
A DV codec known to work well is the one available from Mainconcept
- If you run out of I/O buffers, or if the captured video is jerky or is
having crackly sound, turn off preview and use your camcorders display to monitor
the capture. This frees up a significant amount of CPU resources which otherwise
may lead to the described behaviour.
- Using the mentioned DV codec from Mainconcept
it's even possible to capture from analog sources into DV format in
realtime using AVI-IO. You need a 700Mhz or faster processor for it and an analog
capture device which is supporting the DV resolution for captures (most TV tuner
boards will do). This is having the advantage, that older analog footage does
not have to be rendered in the NLE application if it's used along with DV footage.
- 12-bit audio as it's available with most DV devices is translated into 16
bit 32kHz audio during capture since the PC usually does not understand 12 bit
- A personal not with regard to 12-bit audio. With camcorders it does not make
sense in most cases to use 12 bit audio. 12 bit audio is here to support four
audio channels which usually can't be recorded with a camcorder. Since there is
a reserved amount of space per frame in the DV data stream for the audio, the
space will be used up anyways, so you don't get more recording time or a faster
data transfer by limiting yourself to 12 bit audio. I recommend to always record
with the best audio format available (48kHz 16-bit stereo)
We can't guarantee that AVI-IO works with ALL hardware combinations and situations
that are out there in the market. That's one of the reasons why there is a trial
version of AVI-IO. However, if it does not work the way you are expecting, try
the following things:
1) Capture using VidCap from Microsoft. In case you can't capture using VidCap,
you can be almost 100% sure that the problem is NOT related to AVI-IO.
2) Make sure to use a "good" source for your capture. Try another tape. Also make
sure to capture using the frame rate of your source signal (29.97 fps for NTSC
and 25fps for PAL).
3) Read carefully the Gotchas
section and check if one of the "gotchas" there apply to your situation.
If after following the above things you still think that AVI-IO is doing something
wrong, you can send us an e-mail to describing the problem
PLEASE PROVIDE US WITH THE FOLLOWING INFORMATION!!!!
- The version of AVI-IO you are using -> Help -> about AVI-IO
- The OS type and version
- The hard disc subsystem (ide, scsi, raid and so on)
- The capture hardware used
- As much observations and information as you think we need to understand the problem.
All registered users of AVI-IO will get ALL future major releases of AVI-IO for
free and sent to them by e-mail shortly after release date. A major upgrade is
when the version number before the "dot" is increased. Minor upgrades only
contain bug fixes which don't affect most users or small functional enhancements
which are not very important. In case we find and fix a bigger problem, we
declare the fixed version as a major upgrade. If you feel that you need a minor
upgrade you can get it for free too, but to get it you have to send us an e-mail to
telling us that you need a minor update.
Don't forget that there are no warranties associated with this software.
While we believe that the software is reasonably bug free and well
behaved, we are in no way responsible if the software does not work the
way you would expect it to work. If it locks up your computer,
garbles your floppy disks or hard drive or does any other harmful thing
to your computer - it is entirely your problem. Markus Zingg is not liable
for any infringements or damages of third parties' rights resulting in your
use of this product. Markus Zingg is in not liable for, and does not
warrant the trustworthiness, quality, industrial use, or serviceability of
this product for the supposed purpose or any other purposes.
This information may be subject to change. All brand and product names
are trademarks and/or registered trademarks of their respective owners.
All rights reserved.
(c) 1999 Markus Zingg, Hofmattrain 15, 6033 Buchrain, Switzerland
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